Burned on eBay

I don't buy much on eBay and this is why. A week or so ago I bought something from a seller about whom I knew nothing other than the 99+% positive ratings he (she?) had on eBay. I paid immediately, as I always do, and now I see that a week later this seller has racked up dozens of negative ratings since my purchase. And, he's quit eBay. Looks like my $20 is down the drain.